Hydrazine vibrational bands

Observed Vibrational Bands for the Kaolinite Hydrazine Complex... 

Raman spectra of hydrazine (a) and of the kaolinite-hydrazine (KH) intercalate (b) suspended in liquid hydrazine are shown in Fig. 1. In contrast to the strong IR-active absorption bands characteristic of clay minerals below 1200 cm-1, the corresponding Raman bands of kaolinite are relatively weak. Nonetheless, both the kaolinite and the hydrazine bands can clearly be resolved (Fig. lb). Hydrazine bands occur at 903,1111,1680, 3200,3280, and 3340 cm-1, whereas the kaolinite bands are found at 140 (not shown), 336, 400, 436, 467, 514, 636, 739, 794, and 3620 cm-1. Observation of lower-frequency adsorbate modes below 1200 cm-1 are often obfuscated in IR absorption spectra because of the strong lattice- framework vibrational modes. As the Raman spectrum of the KH complex shown in Fig. la indicate, the lower-frequency modes of hydrazine below 1200 cm-1 can readily be resolved. The positions of die hydrazine bands in the KH spectrum (Fig. lb) are similar to those of liquid hydrazine (Fig. la) and agree well with published vibrational data for hydrazine (22.23.29-31). The observed band positions for the KH complex, for hydrazine, and for kaolinite are listed in Table 1. 

The yield of dissociation products may be small, but sensitive methods of detection can be used. One of these is laser-induced fluorescence, shown schematically in Figure 9.31, in which a second, probe, laser is used to excite fluorescence in one of the products of dissociation. The C02 and probe laser beams are at 90° to each other and the fluorescence is detected by a photomultiplier at 90° to both beams. This technique has been used, for example, to monitor the production of NH2 from the dissociation of hydrazine (N2H4) or methylamine (CH3NH2). The probe laser was a tunable dye laser set at a wavelength of 598 nm corresponding to absorption in the 2g band, where v2 is the bending vibration, of the A2 A, —X2Bl electronic system of NH2, and total fluorescence from the 29 level was monitored. 

The vibrational spectra of hydroxylamine (NH>OH) complexes have been studied by Kharitonov el al. Sacconi and Sabatini reported the infrared spectra of hydrazine (NH2NH2) complexes of the type [M(N2H4)2Cl2], where M is a divalent metal, and assigned the MN stretching bands between 440... 

In the same studies a determination of the vibrational temperature from the relative intensities of bands in the second positive system of N2 gave values in the range 2200-5000 K which did not change with increase in specific energy. Since the rotational temperature, probably close to the gas temperature, was almost 90% lower than the vibrational temperature, the plasma was non-isothermal under the experimental conditions which favored hydrazine formation. The non-equilibrium population of the highest vibrational levels of the nitrogen molecule has been adduced as indirect confirmation of the theory of energy catalysis (see Sect. 3). 

Vibrational data have been reported for NH4 (H20)n, where n = 3-6, in a free-jet expansion." Ab initio calculations for NH4 (Ar)n, where n=l-7, clusters enabled assignments to observed vibrational wavenumbers to be made for such species. A high-resolution study of V12 (antisymmetric amino wagging mode) of hydrazine showed that the band origin was at 937.1557(47) cm " Ab initio... 

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